大半夜睡不着,来个雪花动画

效果:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        html,body {
             100%; height: 100%;
        }
        * {
            margin: 0;
            padding: 0;
        }
    </style>
</head>
<body style="position: relative;">
<canvas id="canvas" style="border: 1px solid; background-color: #000000;  100%; height: 100%;"></canvas>
<div onclick="clickCvs(event)" style="position: absolute; 100%; height: 100%;top: 0;left: 0;">
    <video id="video" controls width="130" height="" style="position: absolute; bottom: 50px;right: 65px;opacity: 0;">
        <source src="yougui.mp4" type="video/mp4"></source>
        <source src="yougui.ogv" type="video/ogg"></source>
        <source src="yougui.webm" type="video/webm"></source>
        <object width="" height="" type="application/x-shockwave-flash" data="yougui.swf">
            <param name="movie" value="yougui.swf" />
            <param name="flashvars" value="autostart=true&amp;file=yougui.swf" />
        </object>
        当前浏览器不支持 video直接播放,点击这里下载视频: <a href="yougui.webm">下载视频</a>
    </video>
</div>
<script>
    const video = document.getElementById('video');
    const cvs = document.getElementById('canvas');
    const ctx = cvs.getContext('2d');
    // 初始化宽高
    const screenSize = { window.screen.width, height: window.screen.height}
    cvs.setAttribute('width', screenSize.width);
    cvs.setAttribute('height', screenSize.height);
    
    let isOpenDoor = false;
    
    // function clickCvs(e) {
    //     isOpenDoor = true;
    //     video.style.opacity = 1;
    //     video.play();
    //     setTimeout(() => {
    //         if (video.requestFullscreen) {
    //                 video.requestFullscreen();
    //         } else if (video.mozRequestFullScreen) {
    //             video.mozRequestFullScreen();
    //         } else if (video.webkitRequestFullScreen) {
    //             video.webkitRequestFullScreen();
    //         }
    //     }, 1500)
    // }

    // 随机一个坐标点
    function randomPos() {
        const x = Math.ceil(Math.random() * screenSize.width);
        const y = Math.ceil(Math.random() * screenSize.height);
        return {x, y}
    }


    function randomSnow() {
        const p = randomPos();
        const r = Math.floor(Math.random() * 3);
        const dis = Math.ceil(Math.random() * 4);
        const blur = 5 + Math.ceil(Math.random() * 5);
        proSnow(p, r, blur);
        return {p: p, r: r, dis: dis, blur: blur};
    }

    function proSnow(p, r, blur) {
        ctx.save();
        ctx.beginPath();
        ctx.arc(p.x, p.y, r, 0, Math.PI * 2 * 180);
        ctx.strokeStyle = '#FFF';
        ctx.fillStyle = '#FFF';
        ctx.stroke();
        ctx.fill();
        ctx.shadowBlur = blur;
        ctx.shadowColor = "#FFF";
        ctx.closePath();
        ctx.restore(); //将变换后的坐标系恢复到之前状态
    }
    
    function proMoon() {
        const sx = cvs.width / 3 * 2 - 20;
        const sy = 150;
        const r = 100;
        ctx.save();
        ctx.beginPath();
        const gradient = ctx.createRadialGradient(150, 100, 50, 200, 200, 600)
        //径向渐变
        gradient.addColorStop(0, 'rgb(255,255,255)')
        gradient.addColorStop(0.01, 'rgb(70,70,80)')
        gradient.addColorStop(0.2, 'rgb(40,40,50)')
        gradient.addColorStop(0.4, 'rgb(20,20,30)')
        gradient.addColorStop(1, 'rgb(0,0,10)')
        ctx.fillStyle = gradient
        ctx.fillRect(0, 0, cvs.width, cvs.height)
        ctx.fill();
        ctx.closePath();
        ctx.restore(); //将变换后的坐标系恢复到之前状态
    }
    
    // 画小房子
    function proHouse(isOpenDoor) {
        
        const house = {
             200,
            height: 400,
            offsetX: 100,
            offsetY: 50
        }
        
        const doorknob = {
            
        }
        
        ctx.save();
        ctx.beginPath();
        ctx.lineWidth = 10;
        ctx.shadowBlur = 5;
        ctx.shadowColor = "#FFF";
        ctx.rect(cvs.width - house.width - house.offsetX, cvs.height - house.height - house.offsetY, house.width, house.height);
        ctx.strokeStyle = '#7F6A5A'
        if (!isOpenDoor) {
            ctx.fillStyle = '#CDA971'
        } else {
            ctx.fillStyle = '#FFFFFF'
        }
        ctx.stroke();
        ctx.fill();
        ctx.closePath();
        ctx.restore(); //将变换后的坐标系恢复到之前状态
        
        if (!isOpenDoor) {
            // 门把
            ctx.save();
            ctx.beginPath();
            ctx.lineWidth = 5;
            const doorknobPos = {x: cvs.width - house.width - house.offsetX + house.width - 20, y: cvs.height - house.height - house.offsetY + (house.height/2)};
            // console.log(doorknobPos)
            ctx.arc(doorknobPos.x, doorknobPos.y, 10, 0,  Math.PI * 2 / 180, true);
            ctx.fillStyle = '#CDA971'
            ctx.strokeStyle = '#7F6A5A'
            ctx.fill();
            ctx.stroke();
            ctx.closePath();
            ctx.restore(); //将变换后的坐标系恢复到之前状态
        }
    }
    
    // 画夜晚的小山丘
    function proHill() {
        ctx.save();
        ctx.beginPath();
        const standY = cvs.height - 100;
        ctx.moveTo(0, standY);
        ctx.bezierCurveTo(cvs.width / 3, standY-80, cvs.width / 2, standY + 40, cvs.width / 1 - 330, standY+50);
        ctx.lineTo(cvs.width, standY+50);
        ctx.lineTo(cvs.width, cvs.height);
        ctx.lineTo(0, cvs.height);
        ctx.lineTo(0, standY);
        const gradient = ctx.createLinearGradient(0, standY, 0, cvs.height);
        //径向渐变
        gradient.addColorStop(0, '#2B2B2B')
        gradient.addColorStop(0.5, '#4a4a4a')
        gradient.addColorStop(1, '#000000')
        ctx.fillStyle = gradient;
        ctx.strokeStyle = '#7F6A5A'
        ctx.fill();
        // ctx.stroke();
        ctx.closePath();
        ctx.restore(); //将变换后的坐标系恢复到之前状态
    }

    // 随机生产雪花
    const snows = [];
    for (let i = 0; i < 600; i++) {
        snows.push(randomSnow());
    }

    // 让雪花飘起来
    // setInterval(() => {
    //     startSnow();
    // }, 60)
    // 利用自带
    const animationFrame = window.requestAnimationFrame || window.webkitRequestAnimationFrame;
    function start() {
        ctx.clearRect(0, 0, screenSize.width, screenSize.height);
        // 月亮(绘画顺序不能乱,否则会被覆盖)
        proMoon(); //这个再最前面
        // 话房子
        proHouse(isOpenDoor);
        //
        proHill();
        //
        for (const snow of snows) {
            snow.p.y = snow.p.y + snow.dis;
            if (snow.p.y > screenSize.height) {
                snow.p.y = -10;
                snow.dis = Math.ceil(Math.random() * 4);
            }
            
            proSnow(snow.p, snow.r, snow.blur);    
        }
        
        animationFrame(start)
    }
    animationFrame(start)
</script>
</body>
</html>
View Code
原文地址:https://www.cnblogs.com/hello-dummy/p/15168732.html